From c2909a6f6a5ab5499e555dea1d1f7d2394e4aa5b Mon Sep 17 00:00:00 2001
From: Marat Fayzullin <luarvique@gmail.com>
Date: Mon, 24 Jun 2024 19:05:01 -0400
Subject: [PATCH] Adding 24kHz-wide LSB-D and USB-D modes.

---
 csdr/chain/analog.py      | 8 ++++++++
 htdocs/lib/Demodulator.js | 6 ++++--
 owrx/dsp.py               | 3 +++
 owrx/modes.py             | 2 ++
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/csdr/chain/analog.py b/csdr/chain/analog.py
index 8d9674b6..d250dc50 100644
--- a/csdr/chain/analog.py
+++ b/csdr/chain/analog.py
@@ -142,3 +142,11 @@ class SAm(BaseDemodulatorChain):
         ]
         super().__init__(workers)
 
+
+class SsbDigital(BaseDemodulatorChain, HdAudio):
+    def __init__(self):
+        workers = [
+            RealPart(),
+            Agc(Format.FLOAT),
+        ]
+        super().__init__(workers)
diff --git a/htdocs/lib/Demodulator.js b/htdocs/lib/Demodulator.js
index 660d90f2..4408348e 100644
--- a/htdocs/lib/Demodulator.js
+++ b/htdocs/lib/Demodulator.js
@@ -9,6 +9,8 @@ Filter.prototype.getLimits = function() {
         max_bw = 12500;
     } else if (['dmr', 'dstar', 'nxdn', 'ysf', 'm17'].indexOf(this.demodulator.get_modulation()) >= 0) {
         max_bw = 6250;
+    } else if (['lsbd', 'usbd'].indexOf(this.demodulator.get_modulation()) >= 0) {
+        max_bw = 24000;
     } else if (this.demodulator.get_modulation() === 'wfm') {
         max_bw = 100000;
     } else if (this.demodulator.get_modulation() === 'drm') {
@@ -249,8 +251,8 @@ function Demodulator(offset_frequency, modulation) {
     this.state = {};
     this.secondary_demod = false;
     var mode = Modes.findByModulation(modulation);
-    this.low_cut = mode && mode.bandpass && mode.bandpass.low_cut || null;
-    this.high_cut = mode && mode.bandpass && mode.bandpass.high_cut || null;
+    this.low_cut = mode && mode.bandpass? mode.bandpass.low_cut : null;
+    this.high_cut = mode && mode.bandpass? mode.bandpass.high_cut : null;
     this.ifRate = mode && mode.ifRate;
     this.listeners = {
         "frequencychange": [],
diff --git a/owrx/dsp.py b/owrx/dsp.py
index 8927b3a2..41a7bb81 100644
--- a/owrx/dsp.py
+++ b/owrx/dsp.py
@@ -619,6 +619,9 @@ class DspManager(SdrSourceEventClient, ClientDemodulatorSecondaryDspEventClient)
         elif demod == "empty":
             from csdr.chain.analog import Empty
             return Empty()
+        elif demod in ["usbd", "lsbd"]:
+            from csdr.chain.analog import SsbDigital
+            return SsbDigital()
 
     def setDemodulator(self, mod):
         # this kills both primary and secondary demodulators
diff --git a/owrx/modes.py b/owrx/modes.py
index e4ba2934..8371ea5d 100644
--- a/owrx/modes.py
+++ b/owrx/modes.py
@@ -124,6 +124,8 @@ class Modes(object):
         AnalogMode("usb", "USB", bandpass=Bandpass(300, 3000)),
         AnalogMode("cw", "CW", bandpass=Bandpass(700, 900)),
         AnalogMode("sam", "SAM", bandpass=Bandpass(-4000, 4000)),
+        AnalogMode("lsbd", "LSB-D", bandpass=Bandpass(-24000, 0)),
+        AnalogMode("usbd", "USB-D", bandpass=Bandpass(0, 24000)),
         AnalogMode("dmr", "DMR", bandpass=Bandpass(-6250, 6250), requirements=["digital_voice_digiham"], squelch=False),
         AnalogMode(
             "dstar", "D-Star", bandpass=Bandpass(-3250, 3250), requirements=["digital_voice_digiham"], squelch=False